Electric target apparatus for indicating hit points

ABSTRACT

A target apparatus for automatically indicating the hit point of a projectile comprises a plurality of target elements mounted one behind the other, each element including two electrically insulated parallel sheets of electrically conductive material and included in an electric circuit, the distance between the two conductive sheets being less than the length of a projectile. At least two of the target elements are situated in planes which are inclined one relative to the other, whereby said relatively inclined target elements, when traversed by a projectile, produce pulses in timed sequence which are used to determine the hit point of the projectile on the target.

United States Patent [72] inventors Armin Scharz;

Oskar Scharz, lnterlaken Bern,

Polytronic S. A. Saint-Aubin (Neuchatel, Switzerland) [73] Assignee {32]Priority Jan. 19, 1968 [33] Switzerland 861/68 [54] ELECTRIC TARGETAPPARATUS FOR [56] References Cited UNITED STATES PATENTS 3,004,76311/1961 Knaff 273/102.2A 3,487,226 12/1969 Yetter et al 273/1022 PrimaryExaminer-Anton O. Oechsle Assistant ExaminerMarvin SiskindAttorney-Ostrolenk, Faber, Gerb & Soffen ABSTRACT: A target apparatusfor automatically indicating the hit point of a projectile comprises aplurality of target elements mounted one behind the other, each elementincluding two electrically insulated parallel sheets of electricallyconductive material and included in an electric circuit, the distancebetween the two conductive sheets being less than the length ofaprojectile. At least two of the target elements are situated in planeswhich are inclined one relative to the other, whereby said relativelyinclined target elements, when traversed by a projectile, produce pulsesin timed sequence which are used to determine the hit point of theprojectile on the target PATENTEU HAY25 |97l 3; 589,579

sum 1 OF 3 PATENTEU m2 5 Ian sum 3 [1F 3 ELECTRIC TARGET APPARATUS FORINDICATING HIT POINTS This invention relates to target apparatus andassociated electric circuitry for use in firearm target practice.

ln prior US. Pat. application Ser. No. 638,692 filed May 2, 1967, nowU.S. Pat. No. 3,529,828, a shooting target is described having at leasttwo electrically insulated, but conductive sheets. These sheets arespaced apart for a distance less than the length of the projectile, sothat upon passage of a projectile through the target a momentaryelectric connection between the two sheets is established. A source ofelectric current and a transformer are connected in series with the twoconductive sheets, Each time a projectile establishes a momentaryelectrical connection between the two sheets, a pulse is generated inthe secondary of the transformer and is transmitted to a recorder andevaluated. After passage of the projectile the two conductive sheets areagain electrically separated.

One of the two conductive sheets can be divided into a plurality ofzones which are electrically insulated from each other, for example intoa central circular zone, corresponding to the field of fire of a decimaltarget and several annular zones disposed concentrically about thecentral zone. With such an arrangement it is possible to obtain a scoreindication which indicates at which distance from the center of thetarget the projectile has hit the target.

A further known arrangement of a target comprises a third conductivelayer which, for example, is divided into a plurality of rectangularsections. Such an arrangement not only enables the score to indicate thedistance of a hit from the center of the target, but also theapproximate position of the hit on the target.

In such targets the conductive layer of each zone and of each section isconnected by means of an electrical conductor to a terminal, and theseconductors also are situated at least partially in the field of fire.The conductors accordingly may also be hit by projectiles and may bedamaged. For this reason, they are so formed as to be able to operateeven if hit by a plurality of projectiles. Further, in such knowntarget, a fine subdivision of the indication, as required for examplewith a decimal or even a centesimal target, are difficult to realize. Inthe latter case, more than one hundred connections to each shootingtarget would have to be provided, and each of these connections wouldhave to be associated with an evaluation circuit.

The object of the present invention is to provide target apparatus whichcan signal the hits of the projectile with a very fine subdivison, andnotwithstanding is of simple construction.

The target apparatus according to the invention comprises a plurality oftarget elements mounted one behind the other, each element including atleast two electrically insulated parallel sheets of electricallyconductive material, each conductive sheet being connected to a terminalincluded in an electric circuit whereby said two conductive sheets ofeach target element are temporarily electrically connected when aprojectile penetrates the two sheets and the respective circuit will beclosed, at least two of said target elements being situated in planesinclined with respect one another, whereby said relatively inclinedtarget elements, when traversed by a projectile, produce pulses in timedsequence, the time interval between the pulses being dependent on theposition of the hit point of the projectile on the target.

The invention will now be more fully explained by the followingspecification, reference being had to the accompanying drawings, inwhich:

FIG. 1 is a front view of a decimal target provided with a socalled-point-graduation;

FIG. 2 is a sectional view taken along line Il-ll of FIG. 1;

FIG. 3 is a perspective view of the basic structure of an other form oftarget;

FIG. 4 shows a device for indicating the position of the hit point;

FIG. 5 is a sectional view through a further embodiment of a target inaccordance with the present invention;

FIG. 6 shows the basic electrical circuit for determining and indicatingthe hit point for a target of FIGS. 1 and 2;

FIG. 7 is a diagram showing the kind of pulses which are produced in thedifferent target elements;

FlG. 8 is a diagram showing the form of a pulse train which transmitsthe position of the hit point from the target to the shooting stand; and

FIG. 9'is a schematic view of an embodiment of a target for determiningthe value of the score and the position of the hit point.

Referring to the drawings, FIG. 1 shows a first embodiment of a targetwhich can generate electric pulses for determining the position of thehit point. In this target a sheet of paper 2, having printed thereon thepattern of a 10-point or decimal target is stretched over and fixed on aframe 1. A supposed hit point ofa fired projectile has been designatedby 3.

As is apparent from FIG. 2 the target comprises a sheet of paper 2 onthe front side as well as three target elements 4,5 and 6 mounted behindthe sheet 2. Each target element comprises a pair of electricallyinsulated conductive sheets 7 and 8, 9 and 10, 11 and 12, respectively,extending over the whole target cross section. The thickness of eachinsulating sheet 13, 14 and 15 provided between said conductive sheetsof each pair is smaller than the length of the projectile which will beshot on the target.

The conductive sheets 7l2 may be made of thin metal foil or ofanelectrically conductive rubber composition. The insulating sheets l3, l4and 15 are preferably made of sponge rubber or foamed plastic material.On the back side of each second conductive layer 8, 10 and 12 is fixedby means of a suitable adhesive further protective sheets l6, l7 and 18,respectively. These protective sheets serve to prevent the secondconductive sheet of each target element from being pulled away by theprojectile.

Due to the fact that the distance between the two conductive sheets ofeach target element is smaller than the length of the projectile, amomentary electric connection is established between the two sheets eachtime a projectile which is usually made of metal, is penetrating throughthem. This electrical connection is interrupted after the projectile hascompletely traversed the target element. Due to their elasticity, theconductive rubber sheets 7 and 8 return after the passage of theprojectile substantially to their original state, so that even in thecase where a plurality of projectiles would hit the target element atexactly the same place a short electric contact during the passage ofthe projectiles through the target element will be established.

The sheet of paper 2 and the second target element 5 are mounted inparallel planes, i.e. they are equidistant over their entire surface,the distance between them being substantially greater than the length ofa projectile. The first target element 4 is mounted in front of thesecond target element 5 and inclined with respect thereto, as shown inFIGS. 2 and 3, the upper edge 19 of the target element 4 being parallelwith the upper edge 20 of target element 5 (FIG. 3). The third targetelement 6 is also inclined with respect to target element 5, while itsside edge 21 remains parallel to the side edge 22 of target element 5.The holes produced by a projectile penetrating the target are designatedin the paper sheet 2 by 3 and in the different target elements 4, 5 and6 by 3, 3" and 3", respectively. Spacers 2328 of different length areused for holding the target elements 4-6 in their respective positionsas described.

As shown in FIG. 6, each of said conductive sheets is provided with aterminal 29, 30, 31, 32, 33 and 34 respectively, arranged outside thefield of fire. The terminals 29 and 30 of the conductive sheets 7 and 8of the first target element 4 are connected in series to a voltagesource 35 and to the primary winding of a transformer 36. As soon as aprojectile penetrates through target element 4 the aforementionedelectric circuit is closed momentarily and a current passes in thiscircuit. This current induces at the terminals of the secondary windingof transformer 36 a short pulse which is fed to the input terminal 39 ofa transducer 42. Upon penetration of the target elements 5 and 6 by the.projectile further pulses are produced in a similar manner in thesecondary windings of transformers 37 and 38. These pulses are of coursedisplaced in time since the projectile cannot penetrate at the same timethrough all three of said target elements which are mounted one behindthe other.

The three pulses 43, 44 and 45 produced in the secondary windings oftransformers 36-38 and shown in FIG. 7 will be transformed in thetransducer 42, to a pulse sequence shown in FIG. 8, whereby the firstflank 46 corresponds to the front flank of pulse 43,flank 47 to thefront flank of pulse 44 and flank 48 to the front flank of pulse 45.This pulse sequence is fed from the output 49 of the transducer to atransmitter 50 and from the transmitter through a lead 51, which can bethe lead of a hitherto used and known signal device (e.g. a bell wire),to a receiver 52 in the shooting stand. This receiver will analyze thesignal and feed it to an indicating apparatus 53.

The position of the target elements 4 and 6 with respect to the targetelement 5 is such that the centers of elements 4 and 6 are equidistantfrom the center of target element 5. The angles of inclination of bothtarget elements 4 and 6 with respect to the intermediary target element5 are identical.

Supposing that a projectile is penetrating through the centers of allthree target elements 4, 5 and 6, there will be produced a pulsesequence similar to that shown in FIG. 8, however, the distance betweenthe flanks 46 and 47 would be the same as the distance between theflanks 47 and 48. If furthermore it is supposed that the velocity of theprojectile remains substantially constant, it is possible to deduce theY- coordinate 55 (FIG. 4) of the hit point from the length of thepositive part of the pulse train and accordingly the X-coordinate 54 ofthe hit point from the negative part of the impulse train. Thesecoordinates can be reproduced on the indicating apparatus (FIG. 4). Thehit point 3 corresponds with the point of intersection of these twocoordinates.

In order to take into account the different velocities of projectilesfired with different kinds of firearms it is possible to use, besidesone target element 5, an additional similar target element which has tobe mounted in parallel relationship to said first element 5, alsobetween the target elements 4 and 6, and preferably at a distance fromthe element 5 which is equal to the distance between the centers ofelements 4 and 5. In this case there will be produced four pulses,instead of three as represented in FIG. 7, the distance between thesecond pulse and the third pulse then furnishing a reference valuedependent upon the velocity of the projectile, and v'vhich can serve forthe evaluation. If for example all three distances between the fourpulses are identical, this would mean that the hit point is exactly inthe center of the target.

A further embodiment of a target according to the invention is shown inFIG. 5. In this form a first target element 55 is mounted just behindthe paper target 2 in the frame 1. A second target element 56 extendingparallel to said first element 55 is mounted at a distance therefromwhich is greater than the length of the projectile. A further targetelement 57 having at least partially the form of a cone surface isarranged behind said second target element 56. The distance between thetarget elements 55 and 56 is the same as the distance between the edgesof the conical target element and the element 56, while the distancebetween the center of element 56 and the center ofelement 57 is fourtimes the said aforementioned distance. This means, in the case wherethe three pulses produced when a projectile penetrates through thetarget elements are mutually equidistant, that: the hit point of theprojectile is in a zone near the edges of the target, while in the casewhere the distance between the second pulse and the third pulse is fourtimes greater than the distance between the first pulse and the secondpulse, the hit point is exactly in the center of the target. This typeof target enables to evaluate the distance of the hit point from thecenter of the target by simply comparing the differences in time of thepulses produced and taking into account the velocity of the projectile.However, this kind of target along (FIG. 5) does not permit to locatethe actual position of the hit point with respect to the center of thetarget.

It is also possible to use a target element of the type of element 57but which, viewed in transverse section, is curved in such a manner thatthe tangent lines to the curve near its center are much more inclinedwith respect to the other flat or plane target elements than the tangentlines in the zones near its edges. By means of such a curved target itis possible to increase the accuracy of indication in the centralportion of the target.

In order that the target of FIG. 5 can also be used for indicating theposition of the hit point, it is possible to provide two inclined planetarget elements similar to the target elements 4 and 6 shown in FIG. 3,or to add a target element whose conductive sheets are subdivided intostrips, whereby the strips of one conductive sheet are arranged at rightangles to the strips of the other conductive sheet, each strip beingfurthermore provided with an electric connection for deter mining theposition of the hit point.

In a further embodiment, represented in FIG. 9, one of the twoconductive sheets ofa target element 55 is subdivided into twelvesectors 58-69, each being electrically insulated from the others.Terminals 708ll are provided for each sector. The remaining part of theconstruction and arrangement of the target elements 55, 56 and 57 ofthis target is similar to that of the target represented in FIG. 5.

That conductive sheet of target element 55 which is not subdivided insectors is connected to the primary winding of a transformer 82 and thislatter to one terminal of a voltage source 83. Each single sector 58-69is connected to the primary winding of one ofa plurality of transformers84-95 (of which only a few are represented), these primary windingsbeing connected in turn to the other terminal of the voltage source 83.lfa projectile penetrates through the sheet of paper 2, e.g. 96, itproduces a hit point 96' in target element 55, a hit point 96" in targetelement 56 and a hit point 96" in target element 57.

When the projectile is penetrating through target element 55 the circuitbetween the voltage source 83, the transformer 82, the not-subdividedconductive sheet of target element 55, the sector 63, the transformerand back to the voltage source 83 will be momentarily closed, therebyinducing a pulse in each of the secondary windings of transformers 82and 90. The pulse produced in transformer 90 s fed to a coder 98 foridentification. The latter produces an electric signal which correspondsto the approximate direction with respect to the center of the target,in which the hit point 96 has been found.

The primary windings of two transformers 99 and are connected in serieseach with a terminal of the target elements 56 and 57, as well as withthe voltage source 83. The current pulses produced in the transformers82, 99 and 100 when a projectile penetrates through the target elements55, 56 and 57 are inducing pulses in the secondary windings of thesetransfonners, which are fed to the time measuring instrument 97. Thetime differences between these pulses permit to determine the distanceof the hit point 96 from the center of the target.

The signals appearing at the output terminals I01 of the time measuringinstrument 97 and at the output terminals of the coder 98 aretransmitted to the shooting stand, where they are analyzed and renderedvisible by an optical indicating device.

The voltage of the voltage source 83 is selected high enough, so thatany possible layer of grease or any oxidation layer on a projectile istraversed. The output of the voltage source is preferably selected sohigh that deformations of the conductive sheets, caused by theprojectile, which could produce a continuous short which are fusedautomatically. In this manner the self-regeneration of the targetelements is guaranteed.

A target as shown and described with respect to FIG. 9 permits an exactindication of the score on a IOO-point or centesimal target and at thesame time a substantially correct indication of the position of the hitpoint.

The electrical connection made by the projectile between theelectrically conductive sheets of each of the target elements isinterrupted after the projectile has traversed said element. However, itis possible that a conductive bridge of electrically conductive materialremains between the conductive sheets. The result of such a bridge wouldbe that a further projectile could not produce a pulse in the winding ofthe associated transformer. In order to avoid such a disadvantage theoutput of the voltage source is selected so that it is able to fuse anyof such remaining bridge. The conductive layers of each target elementare thus always electrically insulated one from the other as soon as theprojectile has left the target ele ment and the target is again readyfor indicating the next hit. These explanations clearly show that thetarget of the present invention is self-regenerating if this should benecessary.

The target can be enclosed by front and rear protective layers, whichare preferably of waterproof or water-repcllant material, e.g. of aplastic material. If the electrically conductive sheets are made of aconductive rubber composition and are mounted on insulated layers ofelastic or plastic material e.g. of foamed polyurethane orpolyvinylchlorid, the holes produced by the projectile willautomatically close, at least partially, due to the elasticity of thismaterial, thereby substantially increasing the life, of the target.

We claim:

1. Target apparatus for automatically indicating the hit point of aprojectile, comprising a plurality of target elements mounted one behindthe other, each element including at least two electrically insulatedparallel sheets of electrically conductive material; each conductivesheet being connected to a terminal included in an electric circuitwhereby said two conductive sheets of each target element aretemporarily electrically connected when a projectile penetrates the twosheets and the respective circuit is closed, at least two of said targetelements being situated in planes inclined with respect to one another,whereby said relatively inclined target elements, when traversed by aprojectile produce pulses in timed sequence, the time interval betweenthe pulses being dependent on the position of the hit point of theprojectile on the target, the full surface area of each of said targetelements being spaced from the full surface area of adjacent targetelements without lines of intersection, whereby said pulses produced bya projectile traversing said target elements always appear in a fixedsequence.

2. Target apparatus as claimed in claim 1, comprising three plane targetelements, wherein the second element is mounted in a plane substantiallyat right angles with respect to the path of target projectile, the firstelement, for determining the ordinate of the hit point, being turnedrespect a horizontal axis to a position in which it is inclined withrespect to the plane of said second element, and the third element, fordetermining the abscissa of the hit point, being turned about a verticalaxis to a position in which it is inclined with respect to the plane ofsaid second element.

3. Target apparatus as claimed in claim 2, comprising a fourth targetelement for determining the velocity of the projectile and positioned ina plan parallel to the plane of said element which is arrangedsubstantially at right angles to the path of the projectile.

4. Target apparatus as claimed in claim 1, comprising two targetelements provided for determining the velocity of the projectile, eachelement being situated in a plane substantially at right angles withrespect to the path of the projectile, and a further target elementhaving at least partially the shape of a cone surface and mounted infront of or behind the said other two target elements for determiningthe distance of the hit point from the center of the target.

5. Target apparatus as claimed in claim 4, in which an electricallyconductive sheet of one of said target elements is subdivided into aplurality of sectors each being electrically insulated from the othersand each being connected to a terminal, thereby permitting to determinethe position of the hit point.

6. Target apparatus as claimed in claim 1, comprising transformer meansfor connecting each of said conductive sheets to a voltage source, apulse changing device for lengthening the short electric pulses producedwhen a projectile passes through said sheets, and an indicator devicefor indicating the lengthened pulses.

7. Target apparatus as claimed in claim 6, in which one terminal of eachof said conductive sheets is connected to one terminal of a voltagesource and the other conductive sheets are connected each by theintermediary of a transformer to the other terminal of said voltagesource to thereby produce an electric pulse when a projectile ispenetrating through a tar get element, means being provided to comparethe time intervals between these pulses and operate a device forlocalizing the hit point.

8. Target apparatus as claimed in claim 7, and comprising a targetincluding at least three flat target elements, a trans ducer totransform the three pulses produced into a pulse train which istransmitted from the target to a shooting stand for being analyzed, andan indicating device for rendering visible the coordinates of the hitpoint.

9. Target apparatus as claimed in claim 8, and comprising a fourthtarget element arranged in a plane substantially at right angles withrespect to the path of the projectile, the pulse produced by this fourthelement when traversed by a projectile being used for determining thevelocity of the projectile and for correcting the said pulse train inorder to increase the accuracy ofthe indication.

10. Target apparatus as claimed in claim 1, comprising two flat paralleltarget element and a third target element in the shape of a conesurface, means being provided for comparing the time intervals betweenthe first two pulses and between the second and the third pulse todetermine the distance of the hit point from the center of the target,and for transmitting a signal corresponding to this. time interval ratioto the shooting stand.

11. Target apparatus as claimed in claim 10, in which one of theconductive layers of one of the said pair of parallel target elements issubdivided into sectors, each of the said sectors being connectedthrough additional transformers to the said voltage source, the pulsesproduced in these transformers being converted by a position-findingapparatus and the output signal of this apparatus being transmitted tothe shooting stand where it is made visible for indicating theapproximative hit point position.

12. Target apparatus as claimed in claim 6, in which the output of saidvoltage source is great enough to fuse conductive bridges remainingbetween the said sheets after penetration of a projectile, so as toregenerate the target.

1. Target apparatus for automatically indicating the hit point of aprojectile, comprising a plurality of target elements mounted one behindthe other, each element including at least two electrically insulatedparallEl sheets of electrically conductive material, each conductivesheet being connected to a terminal included in an electric circuitwhereby said two conductive sheets of each target element aretemporarily electrically connected when a projectile penetrates the twosheets and the respective circuit is closed, at least two of said targetelements being situated in planes inclined with respect to one another,whereby said relatively inclined target elements, when traversed by aprojectile produce pulses in timed sequence, the time interval betweenthe pulses being dependent on the position of the hit point of theprojectile on the target, the full surface area of each of said targetelements being spaced from the full surface area of adjacent targetelements without lines of intersection, whereby said pulses produced bya projectile traversing said target elements always appear in a fixedsequence.
 2. Target apparatus as claimed in claim 1, comprising threeplane target elements, wherein the second element is mounted in a planesubstantially at right angles with respect to the path of targetprojectile, the first element, for determining the ordinate of the hitpoint, being turned respect a horizontal axis to a position in which itis inclined with respect to the plane of said second element, and thethird element, for determining the abscissa of the hit point, beingturned about a vertical axis to a position in which it is inclined withrespect to the plane of said second element.
 3. Target apparatus asclaimed in claim 2, comprising a fourth target element for determiningthe velocity of the projectile and positioned in a plan parallel to theplane of said element which is arranged substantially at right angles tothe path of the projectile.
 4. Target apparatus as claimed in claim 1,comprising two target elements provided for determining the velocity ofthe projectile, each element being situated in a plane substantially atright angles with respect to the path of the projectile, and a furthertarget element having at least partially the shape of a cone surface andmounted in front of or behind the said other two target elements fordetermining the distance of the hit point from the center of the target.5. Target apparatus as claimed in claim 4, in which an electricallyconductive sheet of one of said target elements is subdivided into aplurality of sectors each being electrically insulated from the othersand each being connected to a terminal, thereby permitting to determinethe position of the hit point.
 6. Target apparatus as claimed in claim1, comprising transformer means for connecting each of said conductivesheets to a voltage source, a pulse changing device for lengthening theshort electric pulses produced when a projectile passes through saidsheets, and an indicator device for indicating the lengthened pulses. 7.Target apparatus as claimed in claim 6, in which one terminal of each ofsaid conductive sheets is connected to one terminal of a voltage sourceand the other conductive sheets are connected each by the intermediaryof a transformer to the other terminal of said voltage source to therebyproduce an electric pulse when a projectile is penetrating through atarget element, means being provided to compare the time intervalsbetween these pulses and operate a device for localizing the hit point.8. Target apparatus as claimed in claim 7, and comprising a targetincluding at least three flat target elements, a transducer to transformthe three pulses produced into a pulse train which is transmitted fromthe target to a shooting stand for being analyzed, and an indicatingdevice for rendering visible the coordinates of the hit point.
 9. Targetapparatus as claimed in claim 8, and comprising a fourth target elementarranged in a plane substantially at right angles with respect to thepath of the projectile, the pulse produced by this fourth element whentraversed by a projectile being used for determining the velocity of theprojectiLe and for correcting the said pulse train in order to increasethe accuracy of the indication.
 10. Target apparatus as claimed in claim1, comprising two flat parallel target element and a third targetelement in the shape of a cone surface, means being provided forcomparing the time intervals between the first two pulses and betweenthe second and the third pulse to determine the distance of the hitpoint from the center of the target, and for transmitting a signalcorresponding to this time interval ratio to the shooting stand. 11.Target apparatus as claimed in claim 10, in which one of the conductivelayers of one of the said pair of parallel target elements is subdividedinto sectors, each of the said sectors being connected throughadditional transformers to the said voltage source, the pulses producedin these transformers being converted by a position-finding apparatusand the output signal of this apparatus being transmitted to theshooting stand where it is made visible for indicating the approximativehit point position.
 12. Target apparatus as claimed in claim 6, in whichthe output of said voltage source is great enough to fuse conductivebridges remaining between the said sheets after penetration of aprojectile, so as to regenerate the target.